1. Field of the Invention
The present invention relates to excavating machines. More particularly it relates to an improved bucket type excavator capable of excavating frozen ground, or other ground material of similar hardness.
2. Description of the Prior Art
Bucket type excavators are a well-known class of earth moving equipment. They are characterized generally by an endless chain of buckets supported for tangential entry into ground to be excavated. The Parsons Division of Koehring Company of Newton, Iowa, manufactures both wheel and boom styles of bucket type excavators. Further examples of known bucket type excavators are shown by U.S. Pat. Nos. 3,610,691; 3,663,063 and 3,680,919.
It is also generally known to use roller cutter elements either alone or in combination with drag bits, for cutting hard ground material. Examples of earth excavating machines using roller type cutting means are shown by U.S. Pat. Nos. 2,096,875; 2,244,537; 2,808,253; 3,049,823; 3,139,148; and 3,393,014.